639795156 has 192 divisors, whose sum is σ = 2047180800. Its totient is φ = 153256320.

The previous prime is 639795097. The next prime is 639795173. The reversal of 639795156 is 651597936.

It is a junction number, because it is equal to n+sod(n) for n = 639795099 and 639795108.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 588045 + ... + 589131.

It is an arithmetic number, because the mean of its divisors is an integer number (10662400).

Almost surely, 2^639795156 is an apocalyptic number.

639795156 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 639795156, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1023590400).

639795156 is an abundant number, since it is smaller than the sum of its proper divisors (1407385644).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

639795156 is a wasteful number, since it uses less digits than its factorization.

639795156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1139 (or 1123 counting only the distinct ones).

The product of its digits is 1530900, while the sum is 51.

The square root of 639795156 is about 25294.1723723074. The cubic root of 639795156 is about 861.6819239060.

The spelling of 639795156 in words is "six hundred thirty-nine million, seven hundred ninety-five thousand, one hundred fifty-six".